This invention relates to a body fluid purifying material, to a method for purifying a body fluid by use thereof and to a method for removing organ transplantation rejection factors exhibited in blood.
With progress of medicine, it has become possible to transplant organs such as heart, kidney and liver, but it is a task of crucial importance to inhibit or alleviate the rejection reactions accompanied with organ transplantation. In the prior art, medicaments such as cyclosporin, azathiopurine, etc. have been administered for the purpose of inhibiting rejection reactions, but sufficient care should be paid to the dose of those medicaments because of the side effect possessed by such medicaments.
Various factors are involved in rejection reaction during organ transplantation. Concerning kidney transplantation having many practical cases among organ transplantation of human being, the rejection phenomenon after kidney transplantation has been said to be frequently caused by the immunological reaction which occurs after the lymphocytes of the recipient recognize the doner antigen released from the transplanted kidney as the non-self foreign antigen. For example, when kidney transplantation is performed, anti-T-cell antibody which is deemed to be the important factor for the rejection reaction, particularly important anti-T-warm antibody, is generated in the plasma of the patient. Therefore, if this factor can be removed, the rejection reaction can be inhibited or alleviated.
Plasma exchange has been practiced for the purpose of removing organ transplantation rejection factors to give considerable effects. Plasma exchange therapeutical method is now being widely used as therapeutical means for serious diseases such as chronic rheumatic arthritis, myasthenia gravis, systemic lupus erythematosus (SLE), fulminant hepatitis, posttransfusion purpura, hyperviscosity syndrome, medicament intoxication, thrombotic thrombocytopenic purpura, blood type incompatible pregnancy, sickel cell anemia, acute progressive glomerular nephritis accompanied with vessel inflammation, chronic liver failure, thrombocytosis, cryoglobulinemia, kidney failure by multiple myeloma, cancer, familial hypercholesterolemia, etc.
However, in the plasma exchange therapeutical method, 2 to 4 liters of plasma are required for plasma exchange for one time, and it is very difficult to procure persistently such amount of plasma or albumin.
Under such background, it has been investigated and practiced to purify the plasma separated from a patient and return the purified plasma again into the body of the patient. As one of such methods, there is the method in which hollow fibers of an organic polymeric compound are used. However, this method sieves the plasma components only according to the sizes of molecules, and also removes active ingredients, and also has the drawback that fluctuation of the components removed may be caused by clogging.
Also, the plasma purifying method by use of an adsorbent has been investigated and applied clinically. As the adsorbent for removing unnecessary factors in plasma, there may be included, for example, protein A-supporting adsorbent, DNA-supporting adsorbent, triptophan-supporting adsorbent, methylated albumin-supporting adsorbent, heparin-supporting adsorbent, etc. Among them, those derived from living body, such as protein A-supporting adsorbent, DNA-supporting adsorbent, although excellent in adsorption specificity, have the drawback that lowering in adsorption characteristic will be brought about during sterilization, storage or manufacture. Also, in the adsorbent using an antigen or antibody as the ligand, when the ligand is eliminated from the adsorbent, an immune complex is formed, whereby there is the fear that side effect may be brought about. For such reasons, adsorbents with the use of physiological polymeric material derived from living body as the ligand have many problem in practical application.
Further, as the method for purifying plasma in general, there are the methods to use hollow fibers or adsorbents as mentioned above, but they have not been used for the purpose of removing organ transplantation rejection factors, and also there is not report at all about selective removal of anti-T-cell antibody with an adsorbent.